Adaptive-Modulation Technique in Wireless Infrared Indoor Communications

We consider the idea of rate-adaptive transmission with multiple modulated sub-carriers in order to achieve broadband communication between fixed access point and mobile user terminal in an indoor non-directed infrared wireless system. This technique, known from DSL, and currently under discussion for RF wireless, seems also attractive for IR indoor systems, but needs to be examined under the specific conditions of the wireless optical channel (new problem statement). We perform ideal channel capacity analysis to assess potential data rates in the multi-path IR channel typically present in rooms. Further on, by means of simulations we investigate the throughput maximization for practical systems with the use of bit-loading.